Treatment practice in the elderly patient with chronic lymphocytic leukemia-analysis of the combined SEER and Medicare database

The median age at diagnosis of chronic lymphocytic leukemia (CLL) is 72, but patients enrolled in randomized trials are often a decade younger. Therapy selection and outcomes in the older, comorbid population are less understood. We evaluated treatment patterns and outcomes among 2,985 first primary CLL patients from the linked Surveillance, Epidemiology, and End Results-Medicare database. There were 151 chlorambucil (CLB), 594 rituximab monotherapy (R-mono), 696 rituximab + intravenous chemotherapy (R + IV Chemo), and 1,544 IV chemo-only patients. Patients administered CLB and R-mono were the oldest and had the highest comorbidity burden while patients receiving R + IV Chemo were the youngest and had the lowest comorbidity burden (p < 0.0001). In the multivariate survival analysis, receipt of R + IV Chemo was associated with significantly lower mortality risk vs. IV Chemo-only (hazard ratio (HR) = 0.73; 95 % confidence interval (CI) 0.62-0.87) and a non-significant mortality risk reduction with R-mono vs. CLB (HR = 0.47; 95 % CI: 0.21-1.05). Older age and increasing comorbidity score were significantly associated with higher mortality. These findings suggest that chemoimmunotherapy is more effective than chemotherapy in an elderly population with a high prevalence of comorbidity, and this extends the conclusions from clinical trials in younger, medically fit patients.